Integral-drive magnetometer head



J y 9, 1952 N. E. KLEIN ETAL 2,605,072

INTEGRAL-DRIVE MAGNETOMETER HEAD Filed July 6, 1944 QMQ/MZQW NORMA/V E. KLEIN WALTER H. BRATTA/N Patented July 29, 1952 IN TEGRAL-DR-IVE MAGNETOMETER HEAD Norman E. Klein, Garden City, N. Y., and Walter H. Brattain, Chatham, N. J., assignors to the United States of America as represented by the Secretary of the Navy Application July 6, 1944, Serial No. 543,697

This invention relates to magnetometer heads for use in carrier-mounted portable magnetometer systems of the general type disclosed in pending application Serial No. 529,003, filed March 31, 1944, Magnetic Stabilization System, Donald G. C. Hare.

In stabilized magnetometer systems of the type disclosed in the application referred to above, a detector-magnetometer element is stabilized in space by means of dual magnetometer-controlled orientation systems which cause appropriate rotations of the detector-magnetometer element about two mutually perpendicular axes to maintain it in alignment with the earths magnetic field irrespective of the movements of the carrier. In this system, the required rotations of the detector-magnetometer element about the two rotational axes are effected by means of electric motors mounted in fixed relation to the carrier and controlled by auxiliary orientor-magnetometer elements movable with the detector-magnetometer element.

In the construction of stabilization systems of this general type, it has been necessary to mount the stationary motors at relatively great distances from the several magnetometer elements in order to prevent spurious signals due to the magnetic disturbances caused by the motors. Orienting rotations of the detector-magnetometer element involve relative motion between the several magnetometer elements and the magnetic fields of the two drive motors, causing undesirable interactions and generally unsatisfactory operation unless there is adequate separation between the magnetometer elements and the drive motors.

It is an object of the present invention, therefore, to provide a magnetometer head for use with stabilization systems of the general type herein contemplated which may be made considerably more compact than those heretofore used without significant loss in performance.

In the improved magnetometer head of the invention, the drive motors are mounted integrally with the magnetometer elements and move therewith during all stabilizing rotations. For a better understanding of this and other features of th invention, reference is made to the single figure of the accompanying drawing in which there is shown one embodiment of the invention.

In the illustrated construction, a detectormagnetometer element indicated generally at I!) and paired orientor-magnetometer elements I2 and M are preferably but not necessarily 1 Claim. (01. 248-184) mounted together on an orientor plate or support member illustrated by the numeral I6 in accordance with the teaching of copending application Serial No. 535,158, filed May 11, 1944, Magnetometer Head, Walter H. Brattain, Norman E. Klein and Max S. Richardson. Orientor plate I6 is mounted in a gimbal system for rotation about two mutually perpendicular axes A-A and BB', which will be referred to as the inner and outer axes, respectively. Plate I6 is thus journaled for rotation about inner axis A-A' in bearings supported by the gimbal ring or frame illustrated by numeral l8, which is in turn mounted for rotation about outer axis B-B in bearings illustrated diagrammatically at M and 42 fixed in respect to the carrier. As shown in the above-mentioned copending application Serial No. 535,158, filed May 11, 1944, Magnetometer Head, Walter H. Brattain, Norman E. Klein and Max S. Richardson, by way of example, rotations about the outer axis are controlled by orientor-magnetometer elements 12, while those about the inner axis are controlled by orientormagnetometer elements l4.

Rotations of the magnetometer-element array about the outer axis are effected by means of motor 20, mounted on detector plate 16 with its shaft in alignment with the inner axis, and driving spur gear 22 which engages segmental crown gear 24, fixed in the carrier by frame member All and concentric with the outer axis. It will be apparent that the diagrammatically shown bearings 4| and 42 and frame member 40, all of which are fixed to the carrier, form a stationary mounting frame means for the carrier. Control of this motor in response to the signals derived from orientor-magnetometer elements I2 is eifected by electronic equipment preferably of the general type disclosed in copending application Serial No. 532,144, filed April 21, 1944, Orientation System, Otto H. Schmitt.

Rotations about the inner axis in response to signal derived from orientor-magnetometer elements I4 are effected by means of drive motor 26, mounted on orientor plate IS with its shaft normal to the inner axis. This motor drives pinion 2B, which engages segmental crown gear 30, mounted on gimbal ring l8 and concentric with the inner axis.

It will be observed that in the construction just described, both of drive motors 20 and 26 are mounted on orientor plate It and move therewith as the plate rotates about its two rotational axes during stabilizing movements. Thus it will be recognized that there is no relative movement between the drive motors and any of the magnetometer elements also mounted on the orientor plate, nor between the drive motors and the earths magnetic field. Accordingly, any permanent magnetism, induced magnetism or eddy currents in the drive motors cause no changes in the magnetic field acting on the magnetometer elements during orienting rotations of the magnetometer head, and spurious magnetometer signals are avoided even though the motors are mounted closely adjacent the several magnetometer elements. constant effect on the magnetometer elements due to the motor fields may be also eliminated if desired by means of permalloy shields. A compact magnetometer head is thus obtained without loss in performance due to spurious signals.

What is claimed is:

In a magnetometer head, stationary frame means, a gimbal frame supported for rotation about afirst axis on said stationary frame means, a support carried by said gimbal frame for ro- It will be understood that the tation about a second axis perpendicular to said first axis, a motor on said support, the drive shaft of which is aligned with said second axis, and a drive transmission between said shaft and said stationary frame means for rotating said gimbal frame about said first axis.

NORMAN E. KLEIN.

WALTER H, BRA'I'TAIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,988,521 Sperry, Jr., et a1. Jan. 22, 1935 2,027,393 McCreary Jan. 14, 1936 2,075,797 Blair Apr. 6, 1937 2,315,167 Von Manteufiel et a1. Mar. 30, 1943 2,468,554 Hull Apr. 26, 1949 2,490,628 Isserstedt Dec. 6, 1949 

